11% still play HD2 with a spinning drive? I would've never guessed that. There's probably some vicious circle thing going on: because the install size is so big, people need to install it on their secondary, spinning drive...
It is no surprise to me that people still have to use HDD for storage. SSD stopped getting bigger a decade plus ago.
SSD sizes are still only equal to the HDD sizes available and common in 2010 (a couple TB~). SSD size increases (availability+price decreases) for consumers form factors have entirely stopped. There is no more progress for SSD because quad level cells are as far as the charge trap tech can be pushed and most people no longer own computers. They have tablets or phones or if they have a laptop it has 256GB of storage and everything is done in the cloud or with an octopus of (small) externals.
Presumably only 11% of PC players, approximately 100% of console players will be on SSD.
Even though I have two SSDs in my main machine I still use a hard drive as an overflow for games that I judge are not SSD worthy.
Because it's a recent 20TB HDD the read speeds approach 250MB/s and I've also specifically partitioned it at the beginning of the disk just for games so that it can sustain full transfer speeds without files falling into the slower tracks, the rest of the disk is then partitioned for media files that won't care much for the speed loss. It's honestly fine for the vast majority of games.